U.S. patent application number 10/139187 was filed with the patent office on 2002-12-19 for arrangement for multichannel signal transmission between mobile units.
Invention is credited to Lohr, Georg.
Application Number | 20020193075 10/139187 |
Document ID | / |
Family ID | 7927829 |
Filed Date | 2002-12-19 |
United States Patent
Application |
20020193075 |
Kind Code |
A1 |
Lohr, Georg |
December 19, 2002 |
Arrangement for multichannel signal transmission between mobile
units
Abstract
What is described here is an array for multi-channel signal
transmission between mobile units, consisting of at least one first
transmitter/receiver unit that is coupled to at least one second
transmitter/receiver unit via transmitting means. The inventive
array is characterized by the provision that in said first and said
second transmitter/receiver units respective mutually tuned filter
banks are provided that filter predetermined characteristic
spectral fractions out of the signals to be transmitted, that
combine these signals to form a cumulative signal in the case of
transmission, that pass on these signals to additionally provided
signal regenerators in the case of reception for regenerating the
original signal, and that moreover directional switches are
provided that separate the signals of the transmission and
reception path from each other or that combine transmitted and
received signals in such a way that they will be transmitted via a
common transmitting means.
Inventors: |
Lohr, Georg; (Eichenau,
DE) |
Correspondence
Address: |
ST. ONGE STEWARD JOHNSTON & REENS, LLC
986 BEDFORD STREET
STAMFORD
CT
06905-5619
US
|
Family ID: |
7927829 |
Appl. No.: |
10/139187 |
Filed: |
May 3, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10139187 |
May 3, 2002 |
|
|
|
PCT/DE00/03856 |
Nov 3, 2000 |
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Current U.S.
Class: |
455/61 ;
370/310 |
Current CPC
Class: |
H04B 1/58 20130101; B60R
16/027 20130101 |
Class at
Publication: |
455/61 ;
370/310 |
International
Class: |
H04B 001/00; H04B
007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 3, 1999 |
DE |
199 52 980.9 |
Claims
1. Array for multi-channel transmission of signals between mobile
units, consisting of at least one first transmitter/receiver unit
(1) that is coupled to at least one second transmitter/receiver
unit (3) via transmitting means (2), wherein respective filter
banks (4, 6, 12, 19) are provided in said first and second
transmitter/receiver units, which filter banks filter predetermined
spectral fractions out of the signals to be transmitted, combine
these signals to form a cumulative signal (13, 13b) in the case of
transmission, and pass on these signals to additionally provided
signal regenerators (7a, 7b, 7c, 7d, 17a, 17b, 17c, 17d) in the
case of reception for regenerating the original signal,
characterized in that directional switches (9, 10) are provided
that separate the signals of the transmission and reception path
from each other or combine transmitted and received signals in such
a way that they will be transmitted via a common transmitting
means, and that said filter banks are so designed that they filter
characteristic spectral fractions out of the signals to be
transmitted.
2. Array according to claim 1, characterized in that in the case of
an additional transmission of exclusively unidirectional signals
merely the respective first transmitter/receiver unit (1) comprises
a filter bank (4) that filters characteristic spectral ranges out
of the individual signals to be transmitted and combines them to
form a cumulative signal (13) that is transmitted directly, without
directional switches, to said transmitting means (2), and that
additionally a second transmitter/receiver unit (3) is configured
exclusively for reception, which filters the signals of said
transmitting means out by means of a second filter bank (6) and
communicates them to additionally provided signal regenerators (7a,
7b, 7c, 7d) for signal processing.
3. Array according to any of the claims 1 or 2, characterized in
that in the case of transmission of signals limited in terms of
bandwidth, which may be detected almost over their entire spectrum,
the signal path of these signals is provided exclusively with a
filter bank for reception, without a joining signal
regenerator.
4. Array according to any of the claims 1 to 3, characterized in
that said directional switch presents, in its turn,
frequency-selective characteristics.
Description
[0001] This application is a continuation of pending International
Application No. PCT/DE00/03856 filed on Nov. 3, 2000, which
designates the United States and claims priority of German
Application No. 199 52 980.9 filed on Nov. 3, 1999.
FIELD OF THE INVENTION
[0002] The present invention relates to an array that may be used
to transmit a great number of different signals simultaneously
between units mobile relative to each other.
PRIOR ART
[0003] For transmission of signals between units mobile relative to
each other, various techniques are known. Frequently, sliding
contact arrays are used to this end, such as combinations of
current collectors and contact rails or, in the case of a rotating
movement, slip rings. Moreover, contact-less or non-contacting
systems are known for transmitting signals between mobile units,
which are based on capacitive, inductive or optical effects. In the
majority of applications, it is not sufficient to transmit a single
signal. Mostly the problem is encountered that a great number of
different signals must be transmitted. The costs of an individual
signal path are comparatively high in the known transmission
technologies and, as a rule, they are increased in proportion to
the number of the signals to be transmitted. Moreover, the
situation in terms of space is frequently so narrow that it is not
possible to provide separate transmission paths for all signals. An
enhancement of this problem is described in the U.S. patent
application Ser. No. 4,697,092 mentioning an array that transmits,
in the case of a motor vehicle, on the one hand, a DC signal for
the horn and, on the other hand, a signal modulated by means of a
carrier via the same mechanical slip ring. To this end, the data is
modulated by means of a modulator, e.g. in an FSK mode, and
correspondingly demodulated in the receiver unit. This array
entails the disadvantage that an additional engineering expenditure
is required for modulating and demodulating the signal. Moreover,
the modulation described here increases the bandwidth of the
transmitted signal, and moreover the signal is transmitted in a
higher frequency band in which a better radiation (stray radiation)
is possible. As a result, the EMC characteristics of the system as
a whole (stray radiation and noise tolerance) are substantially
impaired. Apart therefrom, it is difficult to transmit wide-band
signals via largely extended arrangements such as long contact
paths or slip rings having a wide diameter. In this context, it is
particularly important to consider a low frequency at a small
signal bandwidth.
[0004] The U.S. Pat. No. 3,859,469 describes an array for
multi-channel bi-directional signal transmission between two units
connected to each other by a cable. There, the combination or
separation of the signals is implemented by means of different
filters, For example, different spectral fractions are associated
with different directions. A substantial disadvantage of this array
is the reduced bandwidth because the entire bandwidth available for
the transmission through the cable is distributed to both
directions, The bandwidth required for transmission through the
cable corresponds at least to the total of the bandwidths of the
signals for the individual directions. The demand for a bandwidth
above the bandwidth of the useful signals hence entails a distinct
impairment of the EMC characteristics. On the other hand, with a
predetermined fixed bandwidth in transmission the achievable data
or Information throughput is reduced.
BRIEF DESCRIPTIONS OF THE INVENTION
[0005] The present invention is based on the problem of providing
an array for multi-channel signal transmission, which permits a
small number of transmission paths of a transmission means between
mobile units, a multi-channel signal transmission at very good EMC
characteristics and low costs.
[0006] The solution to this problem is defined in claim 1.
Expedient improvements are the subject matters of the dependent
claims.
[0007] An array consists of a first transmitter/receiver unit 1
(the reference numerals set forth below refer to the drawing that
will be explained in the following) and a second
transmitter/receiver unit 3, which are connected by means of the
transmitting means 2 for transmission of signals between mobile
units. Each of these transmitter/receiver units is capable of
transmitting or receiving signals, respectively. Each of these
transmitter/receiver units comprises a filter bank 4 (19) that
filters characteristic spectral fractions out of the signals 5a,
5b, 5d, 5d (15a, 15b, 15c, 15d) to be transmitted, and adds them to
form a cumulative signal 13 (13b) to be transmitted. Moreover,
these transmitter/receiver units include directional switches 9
(10) for adding or selecting transmitted and received signals in a
way selective in terms of direction for combining them to form a
signal that is transmitted by means of the transmitting means 2 to
the respectively other transmitter/receiver unit. Moreover, each of
these transmitter/receiver units comprises a filter bank 12 (6)
matched with the transmitter unit of the respectively other
transmitter/receiver unit, which bank filters the individual
spectral fractions out of the signal to be transmitted, and
disintegrates them again into their fractional signals.
Furthermore, each transmitter/receiver unit comprises a set of
regenerators 17a, 17b, 17c, 17d (7a, 7b, 7c, 7d) that regenerate
signals 18a, 18b, 18c, 18b (8a, 8, 8c, 8d) out of the fractional
signals of the filter bank, which regenerated signals correspond to
the original signals. The regenerators may be amplifiers, for
example, for restoring the original signal level or also
comparators for pulse shaping. These regenerators may equally
include storing elements for regenerating rectangular signals from
short pulses.
[0008] The number of the signals transmitted per direction is
generally not fixed to be as small as 4. In the present exemplary
presentation, the number 4 has been selected for improved clarity.
The number of the signals may also be different in both
directions.
[0009] The term "directional switch" relates to a unit for the
directionally selective separation of signals. Such circuits are
also known by the term "hybrid 4-wire terminating set" or
"directional coupler" in high-frequency technology. With the
application of such a directional switch, signals can be
transmitted in both directions within the same frequency band. It
is also possible, of course, to transmit signals in the opposite
direction by means of different frequency bands without a
directional switch.
[0010] In another expedient embodiment of the invention, a first
transmitter/receiver unit 1 is used on the transmitter side in the
event of a unidirectional data transmission, which unit comprises
exclusively one transmitter unit, as well as a second
transmitter/receiver unit 3 is used on the receiver side, which
unit 3 comprises a receiver unit exclusively. As here signals can
be transmitted only in a single direction, the two directional
switches 9 and 10 may be omitted.
[0011] In a further expedient embodiment of the invention,
individual regenerators may be omitted when the signals to be
transmitted are characterized by the transmitted signal spectrum as
largely as possible. This is the case particularly when
band-limiting signals are transmitted over their entire frequency
band anyhow.
[0012] According to another embodiment of the invention, the
directional switch 9 or 10, respectively, has a design selective in
terms of frequency. With this provision, the overall system may be
realized with a directional switch and filter banks in many cases
at a low expenditure.
BRIEF DESCRIPTION OF THE DRAWING
[0013] In the following, the present invention will be described in
an exemplary form by embodiments, without any restriction of the
general inventive idea and with reference to the drawings that are
explicitly referred to in all other respects as far as all
inventive particulars are concerned that are not explained in
details In the text. In the drawing:
[0014] FIG. 1 illustrates an inventive array;
[0015] FIG. 2 shows an array for the bi-directional
communication:
[0016] FIG. 3 is a view of an exemplary embodiment of the inventive
array;
[0017] FIG. 4 illustrates an exemplary spectral distribution of the
transmitted signals;
[0018] FIG. 5 is an illustration of an exemplary spectrum of a bus
signal, and
[0019] FIG. 6 shows an exemplary bus signal in the time
interval.
DESCRIPTION OF EMBODIMENTS
[0020] FIG. 1 illustrates an inventive array consisting of a first
transmitter/receiver unit 1 that transmits signals to the second
transmitter/receiver unit 3 by means of the transmitting unit for
the transmission of signals between mobile units. The first
transmitter/receiver unit 1 includes a first filter bank 4 that
filters respective characteristic spectral ranges out of the
different input signals 5a, 5b, 5c, 5d and adds them to form a
cumulative signal 13 that is transmitted to the transmitting means
2 by means of a directional switch 9. The second
transmitter/receiver unit 3 receives from the transmitting means 2
the transmitted signal that is separated into transmitted and
received signals bys means of the directional switch 10 and then
disintegrated again into its spectral fractions by means of the
second filter bank 6. The second filter bank 6 is so dimensioned
that its spectral characteristics correspond to the spectral
characteristics of the first filter bank 4 in the first
transmitter/receiver unit. The output signals of the second filter
bank 6 are passed on to signal regenerators 7a, 7b, 7c, 7d that
regenerate an output signal 8a, 8b, 8c, 8d by amplification,
pulse-shaping or other regenerative provisions, which output signal
corresponds to the original signal as largely as possible.
[0021] The second signal path has a corresponding structure in the
opposite direction, The input signals 15a, 15b, 15c, 15d are
processed by means of a further filter bank 19 in the second
transmitter/receiver unit to form a cumulative signal 13b that is
communicated via the transmitting means 2 to the first
transmitter/receiver unit. In the latter unit, a directional switch
9 provides for a distribution of the signals with directional
selectivity and communicates the signals 14b received in this unit
to a further filter bank 12 that is tuned with the filter bank 19
associated with It. The output signals of the filter bank 12 are
then processed by means of appropriate signal regenerators 17a,
17b, 17c, 17d to form the output signals 18a, 18b, 18c, 18d. The
directional switches 9 (10) in this array serve the purpose of
separating the signals of the two signal flow directions from each
other in an unambiguous manner. In this manner, a cumulative signal
13 of the first filter bank 4 is passed on via the directional
switch 9, the transmitting means 2 and the second directional
switch 10 exclusively as signal 14 to the second filter bank 6 for
analysis. The transmitting means 2 must here be designed for
bi-directional data communication. Only a negligibly small fraction
of the cumulative signal 13 should be transmitted as signal 14b via
the directional switch 9 to the further filter bank 12. A signal
transmission to the same side of the moving array is not desired
expressis verbis, does not make sense from an engineering point of
view, and should therefore also be suppressed. Signals should be
transmitted exclusively via the transmitting means 2. The
directional switches may also be expediently designed as
frequency-selective components so that their directional effect
will reach a maximum in particular frequency bands that are used
exclusively for bi-directional transmission.
[0022] FIG. 2 shows an array for unidirectional data transmission
in correspondence with the invention. Here, the first
transmitter/receiver unit is configured as transmitter unit
exclusively. Moreover, the second transmitter/receiver unit is
designed as receiver unit exclusively. Both units are connected to
each other by means of a transmitting unit. As in such a case the
transmitter/receiver units transmit data exclusively in a single
direction the two directional switches 9, 10 may be omitted.
[0023] FIG. 3 illustrates an exemplary embodiment of the inventive
array. This example is intended to support a better explanation of
the principle of the invention. Here, the following signals are to
be transmitted: a slow relay signal 20a with a switching rate of 10
Hz at maximum; an audio signal 21a in a bi-directional manner
within the frequency range up to 3.5 kHz; a first bus signal 22a in
semi-duplex operation with a maximum data rate of 200 kBaud as well
as a second bus signal 23a with a maximum data rate of 4 MBaud in a
first direction as well as a third bus signal 24a in the second
direction with a maximum data rate of 4 MBaud. The filter bank 4 in
the first transmitter/receiver unit now includes the following
individual units: a first filter 25 with a low-pass characteristic,
which permits DC transmission for the relay and has a pass-band up
to a level as high as 20 Hz. A second filer 26 is provided for
processing the audio signal 21a that has a band-pass characteristic
within the frequency range from 100 Hz to 3.5 kHz. A third filter
27 is used to process the first bus signal 22a. This filter equally
presents a band-pass characteristic with a frequency range from 10
kHz up to 800 kHz. The application of band-pass filters is
permissible in the majority of advanced bus systems because they
permit a DC-free or band-limited transmission of the signals with a
suitable coding (bi-phase, bit staffing or other techniques). The
transmission of the signals of the second bus system 23a is finally
realized within a frequency band from 1 MHz up to 8 MHz. As with
these signals, the spectral spacing from the signals of the first
bus system is not wide enough a higher frequency range is filter
out of the rectangular signals of the bus system, rather than using
the base band for the transmission. Because of the band pass
characteristic of the filter, which suppresses the fundamental
wave, only short pulses remain (positive pulses at a rising edge,
negative pulses at a decreasing edge) which are transmitted via the
line. The filter bank 12 of the first receiver contains a filter
with a band-pass characteristic in correspondence with the filter
39 in the second transmitter/receiver unit 3 for receiving the
signals of the third bus system 24a. Here, both filters should
equally present a band-pass characteristic within the frequency
range from 4 MHz to 8 MHz, like the filter 28. A first signal
regenerator 29 serves to convert the pulses limited in terms of
bandwidth, which are transmitted via the transmitting means, into a
signal corresponding to the original rectangular signal. This
regenerator may consist of a comparator with hysteresis in the
simplest case. The signals in the first transmitter/receiver unit 1
of the filter bank 4 as well as of the filter bank 12 are now
combined with directional selection via a first directional switch
9 and coupled to the second directional switch 10 by means of the
transmitting means 2. The latter switch couples the signals in the
second transmitter/receiver unit 3 to the filter bank 6 as well as
to the filter bank 19, again with directional selectivity. The
second transmitter/receiver unit 3 contains a band-pass filter 30
for the transmission of the signals of the second bus system in the
second direction as well as a filter bank 6 that is tuned to the
frequency bands of the filter bank 4. The output signals of this
filter bank 6 are processed by means of appropriate signal
regenerators 36, 37, 38. Signal regeneration of the signal 20b
(galvanic relay signal) is not required. The audio signal 21d is
regenerated by means of a simple amplifier. The first test signal
is converted into a rectangular signal by means of a comparator.
The second bus signal 23b consists merely of short positive or
negative pulses at the output of the filter bank 6. The original
rectangular signal is then regenerated again in the signal
regenerator y means of a comparator with appropriate hysteresis or
by means of another memory element.
[0024] For the sake of improved clarity, the same reference
numerals were assigned to input or output signals, respectively,
which are associated with each other, however, with different
alphabets given below. For example, the signal 20a becomes signal
20b after transmission by the transmission signal; the signal 21a
becomes signal 21b and signal 22a becomes signal 22b, signal 23a
becomes signal 23b, and finally the signal 24d (reverse
transmission direction) becomes signal 24a.
[0025] FIG. 4 shows the distribution into difference frequency
ranges in correspondence with the example according to FIG. 3. The
signal levels are plotted in the diagram versus the frequency. The
low-frequency relay signal 20a is transmitted within the
low-frequency spectrum 31. In the joining spectral range 32, the
audio signal 21a is transmitted. The first bus signal 22a is
transmitted in a middle frequency range 33. Finally, the second bus
signal 23a or 24a, respectively, is transmitted in both directions
within the same spectral range 34. In this case, the directionally
selective separation is not realized by the application of
different spectral ranges but rather by the use of directional
switches. The directionally selective separation is, of course,
also the subject matter of the invention due to the different
signal ranges.
[0026] FIG. 5 illustrates the spectrum of the second bus signal
23a, in correspondence with the example according to FIG. 3, as it
is transmitted via the transmitting means 2. Here, the limited
bandwidth of the signal can be unambiguously recognized. The
characteristic line spectrum derives from the rectangular bus
signal.
[0027] FIG. 6 illustrates the signal of the second bus system 23a,
in correspondence with the example according to FIG. 3, as it is
transmitted via the transmitting means 2. This signal hence
corresponds to the spectrum shown in FIG. 5. The high positive and
negative peaks of the signal are each created at the respective
points of time by which the rectangular signal, which is taken as a
basis, presents positive or negative edges, respectively. A
comparator may detect these positive or negative signal peaks in a
simple manner. The original rectangular signal can hence be
reconstructed by storing it, such as this is done by a comparator
with hysteresis.
* * * * *